1. Technical Field
This disclosure relates to photovoltaic modules and methods of manufacturing photovoltaic modules and, more particularly, to photovoltaic modules and methods of manufacturing photovoltaic modules in which mechanical distortion in the modules is substantially reduced or eliminated.
2. Discussion of the Related Art
One type of flexible photovoltaic (PV) module is formed as a thin-film device on a polymeric substrate. An example of such devices is the Copper-Indium-Gallium-Selenide (CIGS) device. CIGS devices present many challenges in terms of the thin-film deposition processes, device patterning, and final assembly/packaging. Polymer substrates are of great significance since high-temperature variations of the material are adequate to accommodate CIGS processing while the material maintains its dielectric properties, which enables monolithic integration without any additional insulating films.
A fundamental challenge in flexible CIGS devices is in the deposition of a metallic back contact onto the polymer prior to the deposition of the CIGS p-type absorber layer. This back contact makes ohmic contact to the CIGS and allows for current to flow through the device and be collected through interconnects to the leads attached to the electrical load. Thus, this back contact, which is usually a metal, must maintain high electrical conductivity, both before and after device processing. It must also survive the deposition environment for the subsequent thin film deposition steps.